title: Regional homogeneity and resting state functional connectivity: associations with exposure to early life stress.
abstract: Early life stress (ELS) confers risk for psychiatric illness. Previous literature suggests ELS is associated with decreased resting-state functional connectivity (rs-FC) in adulthood, but there are no studies of resting-state neuronal activity in this population. This study investigated whether ELS-exposed individuals demonstrate resting-state activity patterns similar to those found in PTSD. Twenty-seven adults (14 with at least moderate ELS), who were medication-free and without psychiatric or medical illness, underwent MRI scans during two 4-minute rest periods. Resting-state activity was examined using regional homogeneity (ReHo), which estimates regional activation patterns through indices of localized concordance. ReHo values were compared between groups, followed by rs-FC analyses utilizing ReHo-localized areas as seeds to identify other involved regions. Relative to controls, ELS subjects demonstrated diminished ReHo in the inferior parietal lobule (IPL) and superior temporal gyrus (STG). ReHo values were inversely correlated with ELS severity. Secondary analyses revealed decreased rs-FC between the IPL and right precuneus/posterior cingulate, left fusiform gyrus, cerebellum and caudate in ELS subjects. These findings indicate that ELS is associated with altered resting-state activity and connectivity in brain regions involved in trauma-related psychiatric disorders. Future studies are needed to evaluate whether these associations represent potential imaging biomarkers of stress exposure.
authors.affiliation: Laboratory for Clinical and Translational Neuroscience, Butler Hospital, Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence, RI, United States. Electronic address: Noah_Philip@Brown.edu.
authors.forename: Noah S
authors.initials: NS
authors.lastname: Philip
authors.forename: Yuliya I
authors.initials: YI
authors.lastname: Kuras
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Valentine
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Sweet
authors.forename: Audrey R
authors.initials: AR
authors.lastname: Tyrka
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Price
authors.forename: Linda L
authors.initials: LL
authors.lastname: Carpenter
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology* / Q000503:physiopathology*; D016022:Case-Control Studies; D002531:Cerebellum / Q000502:physiology / Q000503:physiopathology; D005260:Female; D006179:Gyrus Cinguli / Q000502:physiology / Q000503:physiopathology; D006257:Head; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009068:Movement; D010296:Parietal Lobe / Q000502:physiology / Q000503:physiopathology; D012146:Rest / Q000502:physiology* / Q000523:psychology*; D013315:Stress, Psychological / Q000503:physiopathology*; D013702:Temporal Lobe / Q000502:physiology / Q000503:physiopathology
keywords: Inferior parietal lobule; Post-traumatic stress disorder; Resting state activity; Superior temporal gyrus